Sewing machine



pri 28, 1931.

F. J. KAUFMANN SEWING MACHINE Filed DSC. 14, 1928 @s Hummm en Sgm 15Sheets-Sheet 1 pr 28, 1931 F. 1. KAUFMANN SEWING MACHINE Filed Dec. 14,1928 15 Sheets-Sheet SEWING MACHINE Filed Deo. 14, 1928 l5 Sheets-Shaw*l3 Filed Dec. 14. 1928 l5 SheetsSheet 4 Snom/Lto@ HazzIvJKau/ marin April28, 1931. F. 1. KAUFMANN SEWING MACHINE Filed Deo. 14, 1928 l5Sheets-Sheet 5 plflE 28, 1931- F. J. KAUFMANN SEWING MACHINE Filed Dec.14, 1928 15 Sheets-Sheet 6 plil 28, 1931. 'Y F 1, KAUFMANN 1,802,430

SEWING MACHINE Filed Dec. 14, 1928 l5 Sheets-Sheet 7 Snom/tto@ pii 28,gl. F1 J, KAUFMANN 1,802,430

SEWING MACHINE Filed Dec. 14, 192B l5 Sheets-Sme?I 8 Vinnie .Iza mann LJL' Cl l tom/l c 13 www@ F. 1. KAUFMANN LSUZAS@ SEWING MACHINE Filed Dec.14, 1928 l5 Sheets-Sheet 9 April 28, 1931.

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April 28, 1931. F. J. KAUFMANN SEWING MACHINE Filed Dec. 14, 1928 l5Sheets-Sheet l0 @5% Gum/n.243

April 28, 1931. F. J. KAUFMANN SEWING MACHINE Filed Dec. 14, 1928 15Sheets-Sheet l1 l NV ENTO R Hank .[/Yazfvzwan MM ATTO R N EY April 28,1931.

F. J* KAUFMANN SEWING MACHINE Filed Deo.

15 Sheets-Sheet l2 April 28, 1931- F. J. KAUFMANN 1,802,430

SEWING MACHINE Filed Dec. 14, 1928 15 Sheets-Sheet 13 Il umulluum ATTO RN EY April 28, 1931. F. 1 KAUFMANN 1,802,430

SEWING MACHINE Filed Dec. 14, 1928 15 Sheets-Shea??l 14 April 28, 1931.F 1, KAUFMANN 1,802,430

SEWING MACHINE Filed Deo. 14, 1928 15 Sheets`-Sheet l5 FnkI/dlfmdlzn33kg 41M @Moment JWM Patented pr. 28, 1931 FRANK J'. IKAUFMANN, 0FTRIBES HILLS, NEW 'YORK SEWING M ACHII'NE Application led December 14,1928. Serial No. 326,070.

This invention relates generally to sewing machines, particularly of thetype known as pop-stitch machines, that is: a machine that simulates theordinary over and under hand stitch.

The main object and feature of the nvention is to produce a machine thatwill meet the very exacting requirements in glove making as touniformity in appearance of a row of stitches and as to durability ofsuch stitches. By this statement it is not intended to imply that themachine finds its usefulness exclusively in the stitching or sewing ofglovesit is merely intended to convey the fact that the machine isparticularly applicable to this field. Obviously the machine can be usedfor4 many other purposes.

In the accompanying drawings the invention is disclosed in severalconcrete and preferred forms in which:

Fig. 1 is a front elevation, partly in section and with parts omitted,of a machine embodying one form of the invention. This View iscomplementary to Fig. 18.

Fig. 2 is an end elevation looking in the direction of arrow 2 of Fig.1.

Fig. 3 is a top plan view of Fig. 1.

Fig. 4 is an end elevation looking in the direction of arrow4: of Fig.1.

Fig. 5 is a Vertical sectional view substantially on the plane of line5-5 of Fig. 1.

Fig. 6 is a horizontal sectional view substantially on the'plane of line6-6 of Fig. 1.

Figs. 7 8 and 9 are views similar to Fig. 6 showing differentpositionswhch the parts will occupy during a cycle of the machine.

Fig. 10 is a vertical sectional view substantially on the plane of line10-10 of Fig. 6.

Fig. 11 is a vertical sectional view substantially on the plane of line11-11 of Fig. 6.

Figs. 12 and 13 are diagrammatic views in perspective of themanipulation of the thread during the slack take-up and tensioningsteps..

Figs. 14 and 15 are enlarged sectional Views through the materialshowing the stitching before and after the tension has been applied tothe sitch.

Fig. 16 is an enlarged sectional detail view of the upper needle chuckof the machine :sFu'bstntially on the plane of line -1616of Fig. 17 is abottom plan view of Fig. 16.

Fig. 18 is a fragmentary front elevation, partly in section, of thematerial feeding mechanism. This view is complementary to Fig. 1.

ig. 19 is a vertical sectional view on the plane of line 19-19 of Fig.18.

Fig. 20 is an end elevation,-looking in the direction of arrow 20 ofFig. 18, partly in section.

Fig. 2l is a detail view, partly in section, of the feed dog and itslifter cam.

Fig. 22 is a sectional view on the plane of line 22--22 of Fig. 21.

Fig. 23 is a fragmentary top plan view showing a modified form of the,invention consisting of a coupling between the take-up devices.

Fig. 24 is a sectional view on the plane of line 24--24 of Fig. 23.

Fig. 25 s a fragmentary detail view of an antifriction means for thetake-up devices.

Fig. 26 is a view similar to Fig. 6 illus- 'trating a modified form ofthe invention.

Fig. 27 is a view in front elevation of a thread-clamping device whichmay be employed in the machine.

Fig. 28 is a sectional view on the plane of line 28-28 of Fig. 27.

Fig. 29 is a sectional view on the plane of line 29-29 of Fig. 28.

Fig. 30 is a plan view, partly in section, of one of the thread-clampingjaws.

Fig. 31 is a view similar to Fig. 6 showing a modified form of theinvention of both Figs. 6 and 26.

Fig. 32 is a View similar to Fig. 8 but showing the constructiondisclosed in Fig. 31.

Figs. 33 and 34 are fragmentary views showing modifications of the formof the invention disclosed in Figs. 31 and 32.

The inherent difficulty with sewing machines of the type underconsideration rethe thread after the slack has been taken up. 'Thisdistinction will be readily apprehended by a consideration of Figs. 14and 15 where 1 and 2 indicatetwo layers of material stitched together bymeans of thread In Fig. 14 every stitch, except the last one 4, has beenplaced under suitable and substantially uniform tension; stitch 4 hasmerely had its slack taken up. In Fig. 15 stitch 4 has been placed undersuitable tension. Before proceeding to -a detailed consideration of themeans whereby suitable and uniform tension is applied to a succession ofstitches it may be well to describe the general organization of themachine, which machine involves a number of inventive features.

The machine is characterized by the use of a double-pointed needle 5having a centrally disposed eye 6 that receives thread 3,

which thread is doubled back upon itself and has its free ends tiedtogether with a knot 7. 8 and 9 (Fig. 1) represent an upper and a lowerneedle chuck the needle passing through the material to be sewn andalternately held rst by one and then by another of said chucks. Eachchuck is carried by a spindle 10 that reciprocates in suitable guides as11 carried by the framework or upper and lower sewing heads 12. Suitablemeansare provided for reciprocating spindles 10,- and thereby thechucks, said means, in the present instance, taking the following form.13 indicates a lever, pivoted at 14 and actuated by cam 15 (Fig. 5) bymeans of cam-actuated member 16. At its other end, lever 13 is connectedby means of link 17 (Fig. 1) to collar 18 fast on spindle 10.

The train of connections just described arein duplicate, one train beingfor the upper and the other for the lower needle chuck and theconstruction is exactly the same; the timing of the two trains ofconnections is, however, reversed one with respect to the other, as willbe understood, so that thev needle will pass from one chuck to the otherin proper sequence. The needle chucks may' be constructed in manydifferent ways, but a preferred construction (Figs. 16 and 17 )A is asfollows: 19 are two chuck members forming a grasping means for theneedle,` and these chuck members are carried by a cam sleeve 20 inthreaded engagement at 21 with spindle 10. It will be apparent thatrotation in one direction will raise the sleeve and bring the chuckmembers closer together and that rotation in the other direction willlower the sleeve and thereby admit' of the chuck members being movedapart. Any suitable means may be utilized to open and close the chucksbut, in this instance, cam sleeve 20 is provided with two wings 22 thatare acted upon by members 23 (Figs. 1, 3 and 4) pivoted at 24 and heldin non-active position by spring 25. 26 indicates a rotatable memberhaving dogs 27 to yieldingly engage members 23. It will be understoodthat there are two members 23 associ-V ated with each chuck, one to actagainst each wing 22, and one to open and the other to.

mounted on shafts 28 each carrying a pinion 29 meshing with a or 32.

intermediate the upper and lower chucks is a sewing table 33 on whichthe material to be sewn is placed, and adjacent this sewing table andintermediate the upper and lower sewing heads are the take-up devices 34and 35. It will be seen from Fig. 1, and from the description so fargiven, that the arrangement of the parts forms a very compact and,notwithstanding this, an accessible construction. inasmuch as the twotakeup devices are constructed alike and differ merely in their timing,it will be sufficient to describe only one of them.

Cam shafts 31 and 32 are geared together by means of gears 36 and 37 andmeshing with these gears are pinions 38 and 39 on shafts 40 and 41.Shaft 40 happens to be the power shaft but it will be obvious that powercan be applied at any point to this train of connections. 42 and 43 areupright shafts mounted in the sewing heads and having here abuttingengagement (Fig. 10) in the sewingT table but are independentlyrotatable. Suitable means to drive shafts 42 and 43 at certain statedintervals are here constructed as follows: 44 indicates a bevel gear on(say) shaft 42 meshing with a corresponding bevel gear 45 on horizontalshaft 46. Between shafts 40 and 46 (or 41 and 46) is a clutch device 47which, when thrown in, causes rotation of shaft 42 (or 43). The clutchis controlled from cam 48 that engages cam roll 49 (Fig. 4) on lever 50pivoted at 51, said lever being normally held in engagement with cam 48vby means of 'a spring 52. The upper end of lever 50 engages bifurcatedend 53 of bell crank 54 pivoted at 55 and having a pin 56 engaged ingear 30 on cam shaft 31 slotted clutch arm 57 pivoted at 58. Clutch arm57 engages in a groove 59 of movablel member of clutch 47. Spring 60tends `to close the clutch and cam 48 is utilized to open it, and thatis really the onl significance of the train of connections escribed. Tostop shaft 46 exactly at the end of one revolution, said shaft may beprovided with a notched disk 46EL into which one end of arm 54 enterswhen clutch 47 is thrown out. The upshot of the matter is that shaft 42(or 43) is rotated at certain intervals in harmony with the other partsof the machine. Mounted on shaft 42 (or 43) is a cam 61 which I shallcall a slack take-up and tension cam. 62 is a member or reel surroundinga concentric4 portion of cam 61 and mounted to rotate freely, and 63 isa take-up member or arm pivoted at 64 on the reel and provided with acam engaging portion 65. A spring 66, the tension of which can beadjusted by threaded stem 67 in bracket 68, keeps portion 65 inengagement with cam 61. 69 is a stop to prevent undue movement of arm63. Said arm 63 is provided with an extensible portion 70, slidinglymounted in said arm and provided with a loop engaging finger 71. 72 is aspring having one end anchored on the reel and the other on portion 70,said spring tending to urge portion into a retracted position. Pivotallymounted at 73 on the reel is a cam lever 74 having cam roll 75 and aslotted portion 76 engaging pin 77 of extensible portion 70. 7 8 is whatI shall call an orbit-directing cam, relatively stationary with respectto the turning movement of the reel but adjustable in a manner presentlyto be described. When the needle has been passed through the materialand transferred to the upper needle chuck (we will say) then clutch 47is thrown in and shaft 42 begins to rotate carrying with it cam 61 whichby its engagement with 65 causes rotation of the upper reel, the partsbeing now in the position shown in Figs. 3 and 6. As the reel rotates,cam roll 75 will engage cam 78 and will cause portion 70 to be projectedoutwardly against the tension of spring 72. This will cause finger 71 totravel in an orbit that intersects the plane of the needle or the loopof the thread (Fig. 7). Continuing its movement, the reel will now carrycam roll 75 past the high point of cam 78 andl member 70 will thereforebe retracted by spring 72. By referring to Fig. 12 it will be seen thatduring this period member 7 0 is pulling the slack thread through thematerlal, the other end of the thread being looped over finger 71 ofmember 70a of the lower reel which is not being driven by shaft 43 atthis time and thereby causing the latter to rotate idly in a directionopposite to that of the upper reel. This continues until the lower loopof thread is freed from .pivot 64 and thereby causing 65 to 70a and allthe slack thread has been drawn through the material. It will be evidentthat a point will eventually be reached where the thread will offersufficient resistance to the advance of the upper reel and member 70 tocause compression of spring 66 thereby causing member 63 to swing aroundtravel up surface 79 of -cam 61 (see Fig. 8). The rise of surface 79 andthe tension of spring 66 therefore determines in each instance theamount of tension that the thread is placed under after the slack hasbeen taken up and it will be obvious that the amount of tension to whicheach stitch is subjected will be uniform. The length of time duringwhich clutch 47 remains in is determined by the initial free length ofthe thread used and cannot exceed one revolution of shaft 42 and cam 61.It will be seen, however, that as the free ends of the thread diminishin length, thc predetermined period during which the tension is appliedoccurs earlier and yet earlier in the cycle of operations, but that theduration of said period remain constant and that the amount of tensionapplied also remains constant or uniform. The result therefore is that65 will disengage 79 earlier and earlier as the operation proceeds, butshaft 42 and cam 61 will always complete a revolution (when clutch 47 isthrown out) and will come to rest at the same point each time ready forthe next cycle. Or to put this matter in different language: the twooscillatory take-up devices are opposed to each other and act inalternation, and each take-up device has intermittent periods ofactivity of diminishing duration as the sewing progresses, but thisintermittent period is divided into a slack take-up period `thatdiminishes after each alternation or as the length of the threaddiminishes, but, on the other hand, the stitch tensioning period remainsconstant regardless of the length of the thread. Analyzing the mechanicsof the situation, it is clear that shaft 42 (or 43) is a driving member,reel 62 a driven member and cam 61 and member 65 constitute a releasabledriving connection between members 42 and 34 and that the stitchtensioning period coincides with the release period of 61 and 65. Whennow finger 71 of member 7 0 of the lower reel takes hold of the thread,after the next stitch has been made, the upper reel will be pulled backor rotated reversely, under the influence of the pull of the thread,until said reel again occupies its original position with 79 against' 65ready for the next cycle. During the return movement of the upper reel,cam roll 75 will again pass through cam 78, but, as it is not nowdesired to have finger 71 travel in an orbit that passes through theplane of the needle, said cam 78 is shifted so as to make cam roll 75reach the high point 8O earlier and the orbit of member and lin er -71will therefore be as indicated in ig. 9. Any suitable means may beemployed to shift cam 78 but in the present instance they are asfollows: cam 78 is carried by a ring 81 surrounding a concentric portlonof cam 61;' and connected to ring 81 1s anarm 82 pivotally connected at83 to bell crank 84. Said bell crank 84 is pivotally supported at 85 andcarries a'cam-enga ing member 86 to engage in cam'87 on sha t 31. Thetiming of cam 87 is such that when the reel is rotating idly on thereturn movement cam 78 will be in the position shown in Fig. 9, and,when the reel is moving under compulsion of shaft 42 and cam 61, cam 78will be in the positionshowninFigs. 3, 6, 7 and 8.suitable"brakemechanism, for the reel, is employed, and this ,brakemechanism may conveniently be operated by cam87 because the timing ofthe brake mechanism can be the same as the timing of the shifting of cam78. Accordingly, 88 indicates a brake member, here in the form of arollcarried by arm 89 pivotally supported at 90 on arm 84, and it willbe seen that when arm. 84 is moved by cam 87, to'shift ring 81, brakemember 88 will be moved toward or away from the periphery of the reeldepending upon the direction of the movement of arm 84. The parts are soarranged that, when the reel is being moved by shaft 42, the brake bmember is in engagement with the periphery of the reel, so that, whenshaft 42 ceases to drive the reel, the latter will immediately bebrought to a state of rest, and, when the reel is rotating idly in areverse direction, the brake member is not applied to the saidperiphery. 91 indicates a spring urging the brake member toward the reeland v92 is a stop to limit the motion of said brake member. It will beunderstood that, while l have described in detail only the constructionof the parts associated with the upper reel and take-up device, there isa complementary arrangement of parts associatedv with the lower reel andthe same reference characters will describe the lower construction,always bearing in mind, of course, that the lower reel and take-updevice operate in alternation with the upper one and that therefore, asshown by the drawings, the timing of the lower parts is the reverse ofthe timing of the upper parts.

Suitable means are provided to feed the material during the sewingoperation, and, in the present case, these means take the followingform: referring to Figs. 18 to 22, 93 indicates a cam mounted on camshaft 32, which cam, by means of lever 94, link 95 and lever 96 controlsthe movement of the movable member of clutch 97. Clutch 97 is interposedin the shaft connection 98 that derives its motion from gear 37 by meansof pinion 99 and the arrangement is such that, whenever lever 94 assesover the high spots of cam 93, cliitch 97 is thrown in and shaft 98 i'srotated. Shaft 98 carries a gear 100 that meshes with intermediatepimons 101 which in turn drives pinion 102. i Pinion 102 driveseccentric rollers 103' one of which engages in slot 104 and the other ofwhich engages in slot 104 of feed dog 105, which latter has a slottedend 106 that is supported by pin 107 on the framework. By the foregoinmeans the material is advanced one step a er each passage of the needlethrough the material, feed linger 108 engaging the material and, incon'unction with the usual presser foot 109, e ecting proper movementthereof.

The general operation of the machine is as follows: When the sewingoperation is begun we will assume that the needle is in upper needlechuck 8. The needle is threaded, the thread is doubled back upon itself,the free ends thereof are tied together by a knot 7 (Fig. 14) and thethread is left hanging in sewing table 33. Upper needle chuck 8 nowdescends, passing the needle through the material and placing it withingrasping range of lower needle chuck 9, which latter at this time is ina position close to the under side of sewing table 33. Lower chuck 9 nowgrasps the needle and upper chuck 8 releases it. The lower chuck eginsits downward movement thereby carrying the thread through the material.Lower take-up device 35 now comes into action by throwing in lowerclutch 47 and finger 71 of arm 70 engages the double thread and draws aloop our strands) and takes up the slack. rlhis action continues untilthe entire length of thread has been pulled through the material whenthe resistance of the thread causes member 65 to ride up inclinedsurface 79 of cam 61 thereby applying the required tension to thestitch. During rotation of take-up device 35 brake 88 has been appliedto the periphery thereof so that when the reel stops rotating there willbe no rebound. Cam 61 completes its rotation and lower needle clutch 47is thrown out. The goods or material is now fed forward one step by feedfinger 108. Lower chuck 9 now begins to rise, carrying the needle withit and passing it through the material. The needle is now grasped byupper needle chuck 8 and released by lower needle chuck 9. Upper needlechuck 8 now begins to rise and upper take-up device 34 begins to rotateby reason of upper clutch 47 being thrown in, and finger 71 of arm 70engages the thread. Meanwhile brake 88 of lower take-up device 35 hasbeen released so that said lower takeup device is free to rotatebackwardly under the pull of the thread, and cam 78 has been shifted soas to deflect finger 71 of arm 7 0EL out of the plane of the needle. Thepulling Cil action of upper take-up device 34 continues until the lowertake-up device releases the thread after which the required tension isapplied to the stitch. The material is now fed forward another step byfinger 108. The sewingV operation now continues, the thread becomingshorter with each stitch, Auntil the length of thread has been used up.

Some incidental features remain to be described. If desired the upperand lower reels may be coupled together as shown in Figs. 23 and24 where110 and 111 indicate two friction disks that respectively engage theupper and lower reels. Said disks are rotatably mounted in pivotallysupported arms 112 and 113. Disk 110 carries a gear 114 and disk 111carries a similar gear 115,

' said gears being held in mesh with each other by spring 116. It willnow be seen that rotation of either of the reels in a certain directionwill impart an equal movement to the other reel in the oppositedirection, although the construction, as shown, admits of slippage so asto prevent jamming of the a device is shown in Figs. 27 to 30.

parts. The remainder of the construction involving shafts 42 and 43 aswell as cams 61 etc. remains the same.

In Fig. 25 is shown a` means to reduce friction on the thread, saidmeans consisting of an anti-friction roller or glass pin 117 that may beemployed in place of mere projections like 118.

In Fig. 26 is shown a means to cushion or relieve undue strain on thethread that may be caused by cam roll 75 in passing over the high point80 of cam 78, such means consisting in anchoring one end of spring 72 onbell crank 119 pivoted at 120 on bracket 121 and having a cam roll 122that engages in cam 123 on shaft 42 (or 43) which has a low spot 124that corresponds to high spot 80 so that the parts may yield. A spring125 is associated with119 to oppose the action of roll 122 with respectto the low spot 124.

It is advantageous to relieve the needle of the side thrust of thethread, especially when applying the required tension to the stitch.ployed an abutment 126 (see especially Figs. 12 and 13) around which thethread passes and which thus, rather than the needle, receives thestrain. But, if desired, a more positive device `may be employed. Such127 and 128 indicate two complementary thread clamping jaws mounted on acarrier 129 that is pivotally supported at 130 on pivot 24 and which hasan arm 131 that is acted upon by a cam 132 conveniently carried by shaft28. A spring 133 keeps 131 in engagement with the cam. 127 is here astationary jaw and 128 a movable jaw, the latter being pivoted to theformer at 134;- and a spring 135 tends to urge the jaws irto their Forthis reason there may be em-v 139, also conveniently carried by shaft28, -v

actuates a bell crank 140 that engages the top of rod 137 to depress thesame, at certain intervals, to thereby open movable jaw 128. It will benoted that carrier 129 and bell crank 140 are pivoted on the same center(24) and a spring 141 keeps 140 in engagement with cam 139. Atappropriate times (when one orffthe other of the take-up devices isactive) carrier 129 swings into position with respect to the needle andthread and the jaws are closed to clamp the thread and to thereby assumethe strain so that none of it will fall on the needle. The conformationof the faces of the clamping jaws will be such as will be effective -todo the work. In the present case they are triangular as seen best inFig. 27.

In Figs. 31 and 32 is shown a further modification of the take-updevice. Refer for a moment to Fig. 8 where it will be seen that, afterthe slack thread has been taken up, tension is imparted to the stitchduring the period that 65 passes up incline 79, and also that duringthis period spring 66 becomes compressed or has its tension verymaterially increased. It is advantageous not to have the threadsubjected to too great tension, and for this reason th'e device shown inFigs. 31 and 32 has been produced. It will be seen that spring 66ainstead of being anchored at a fixed point (as in Fig. 8 or Fig. 26) iscarried by lever 150 which latter is pivoted at 151 on arm 63. 152indicates an abutment, eXtraneously of arm 70 and lever 150, with whichengages surface 153 of lever 150. It will now be evident that surface153 can be an arc of a circle the center of which is pivot 64 and that,theoretically, there need be no additional compression of spring 66awhen the thread moves arm 63 on pivot 64 against the tension of spring66a. Surface 153 may be adjustable as by being pivoted at 154 and bybeing provided with a ratchet-andpawl device 155, and it will beunderstood that by the tilting of surface 153 out of its concentricposition the tension of spring 66EL can be either increased or decreasedwhen arm 63 swings around pivot 64 due to resistance of the thread andthe coaction of 65 and 79. In Figs. 31 and 32, the features of Fig. 26happen to be included but it will be evident that the invention is in nowise dependent on the construction of Fig. 26. As a matter of fact, themeans shown in Figs. 31 and 32 are susceptible of use in machines otherthan sewing machines and constitute an independent invention that may beembodied in widely different forms.

